
where \(\pi _{Y_v,\lbrace Y_{u}\rbrace _{u\in \mathcal {N}_v}}\)  denotes their prior distributions of node labels. Note that here we simplify the problem and consider only 1-hop neighbors by following the setting [1]}. In practice, most GNN models can only work on local networks due to the scalability constraints [2]}, [3]}, [4]}. Even with the above simplification, the above MAP estimation is generally intractable.
